name-rev: use OPT_HIDDEN_BOOL for --peel-tag

name-rev: use OPT_HIDDEN_BOOL for --peel-tag

adfc1857bd (describe: fix --contains when a tag is given as input,
2013-07-18) added the option --peel-tag, defining it using a positional
struct option initializer and a comment indicating that it's intended to
be a hidden OPT_BOOL.  4741edd549 (Remove deprecated OPTION_BOOLEAN for
parsing arguments, 2013-08-03) added the macro OPT_HIDDEN_BOOL, which
allows to express this more succinctly.  Use it.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>